The long-term objective of this project is to describe conformational changes in voltage dependent channels to correlate the function to the molecular structure. The specific aims are:(i) the development of an optical detection microscope based on surface enhanced coupled plasmon resonance, (ii) development of the biological preparation based on cells or supported bilayers to be compatible with the new microscope and (iii) measurement of conformational changes associated with voltage gating by following the fluorescence changes of probes attached in specific sites of the channel in study using the system developed in (i) and (ii). It is expected that this new system will have improved signal to noise ratio in the fluorescence due to a decrease in background and an enhancement of the fluorescence by surface plasmon coupling. The results are expected to give direct information on the time course of conformational changes that occur during the operation of voltage-gated channels. As voltage-gated channels play a fundamental role in nerve and muscle excitation, this study is expected to contribute to the understanding of basic mechanisms of excitability at the molecular level and help in formulating therapies in disease.